User Guide

8 Tutorial: Fittin

Model Data (Bipolar Transistor)

Example: If Evaluate is set to YatX(Ic(Q1),!) and if the X

column of the external data file contains the values (

1v, 2v, 3v),

then the PSpice Optimizer will form the Probe goal function

expressions

YatX(Ic(Q1),1v), YatX(Ic(Q1),2v), and

YatX(Ic(Q1),3v), and send each one to Probe for evaluation

against the simulation results.

Monitorin

Pro

ress

with Probe

When optimizing, the PSpice Optimizer (with the help of

PSpice) generates intermediate results which you can have sent

to Probe for viewing. This is especially useful when fitting

model parameters. For the BJT example, this means you can

monitor how closely the Ic and Ib values match the target values.

To set up Probe and the PSpice Optimizer to

monitor the fittin

process

In Schematics, from the Analysis menu, select Simulate to

simulate the circuit.

Create or use an existing Probe display configuration. For

the BJT example, a display named icibe is predefined. To

see what the icibe display looks like:

In Probe, from the Tools menu, select Display Control.

In the display list, click

icibe(DC).

Click Restore.

Click Close.

From the File menu, select Close.

Refer to online Help in Probe for